Preparation and characterization of Al11Cr4 phase by diffusion of Al/Cr composite film

Al-Cr alloys were prepared by making Al/Cr composite films go through a low temperature heat treatment. Al/Cr composite films were electrodeposited from aqueous solution and ionic liquid successively. The effects of the composition of Al/Cr composite film on the phase constitutions of Al-Cr alloy were then investigated. The samples were characterized by metallographic microscope (OM), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and spherical aberration corrected transmission electron microscope (Cs-TEM). The decomposition temperature of Al-Cr alloy was studied using differential thermal analysis. The results showed that single Al11Cr4 phase can be obtained from the Al/Cr composite film at the composition range of 75.0-76.0 at.% Al. The Al11Cr4 would decompose into Al4Cr and Al8Cr5 at 829 °C.